Objective:To assess the ovicidal and larvicidal activities of aqueous and ethanolic extracts of pawpaw seeds Carica papaya（Caricaceae） on the eggs and first stage larvae（L<sub>1</sub>） of Heligmosomoid...Objective:To assess the ovicidal and larvicidal activities of aqueous and ethanolic extracts of pawpaw seeds Carica papaya（Caricaceae） on the eggs and first stage larvae（L<sub>1</sub>） of Heligmosomoides bakeri.Methods:Eggs of this parasite were obtained from experimentally infested mice（Mus musculus） and larvae were from eggs after incubation at 25℃for about 72 hours.The eggs and larvae were exposed to ten different concentrations（0.125,0.25,0.375,0.5, 0.75,1.0,1.25,1.75,2.25 and 2.75 mg/mL） of both aqueous and ethanolic extracts respectively for 72 hours.Distilled water and 0.05%ethanol used as placebo and negative control,respectively. Results:Placebo and negative control group all showed average 92%embryonnation,98%egg hatching and 2%larval mortality,and did not affect development and larval survival.The extracts inhibited embryonic development,egg hatching and larval survival.In general,the ovicidal and larvicidal activities increased with increasing concentration of different extracts.The aqueous extract was found to be more potent on eggs than on larvae.At 2.75 mg/mL,only 8%of eggs embryonnated and 50%hatched to L<sub>1</sub> vs 57%embryonic development and 79%hatching occurred in the ethanolic extract.However,this later extract was more efficient in preventing larval development producing 96%mortality as against 68%with the aqueous extract.Conclusions: These results shows the ovicidal and larvicidal properties of aqueous and ethanolic pawpaw seeds extracts.展开更多
Objective:To evaluate the ovicidal and larvicidal activities of aqueous and ethanolic extracts of leaves of Dichrocephala integrifolia(D.integrifolia)against the eggs(fresh and embryonnated),the first and second larva...Objective:To evaluate the ovicidal and larvicidal activities of aqueous and ethanolic extracts of leaves of Dichrocephala integrifolia(D.integrifolia)against the eggs(fresh and embryonnated),the first and second larval stages of Heligmosomoides bakeri.In order to verify if this medicinal plant possesses active compounds capable of inhibiting the embryonation and hatching of eggs or to induce the mortality of larvae(L1 and L2).Methods:Dried extracts were diluted in distilled water to obtain five different concentrations:625,1 250,2500,3750 and 5000μg/mL.Fresh eggs obtained from artificially infected mice feces were exposed to these different concentrations for 48 h.Time of contact for embryonated eggs was 6 h while L1 and L2 larvae were exposed for 24 h.Distilled water(placebo)and 1.5%DMSO were used as negative controls.Results:Distilled water,and1.5%DMSO had no effect on embryonation,hatching and larval survival.Aqueous extracts of D.integrifolia showed a weak activity against all stages of the parasite at all concentrations tested.On the contrary,the ethanolic extract of D.integrifolia inhibited the embryonation of 87.5%of fresh eggs,the hatching of 81.1%of embryonated eggs and induced the mortality of 98.1%and 98%of L1 and L2 larvae respectively at 5000μg/mL.Conclusions:The results of the present study indicate that the ethanolic extracts of D.integrifolia contained compounds with ovicidal and larvicidal properties.In spite of these results,in vivo tests,studies on toxicity and mechanism of action of active compounds are also needed to validate the utilisation of this medicinal plant by population of Dschang-Cameroon to treat gastro-intestinal parasites.展开更多
To test effect of a synthetic Aluminium-Magnesium Silicate (AMS) on anthelmintic efficacy of piperazine citrate (PC), 35 mice were infected by dosing each, 0.15 ml Helignosomoides bakeri sample which contained 200 inf...To test effect of a synthetic Aluminium-Magnesium Silicate (AMS) on anthelmintic efficacy of piperazine citrate (PC), 35 mice were infected by dosing each, 0.15 ml Helignosomoides bakeri sample which contained 200 infective larvae, per os. Following comfirmation of establishment of infection by faecal floatation, they were assigned into seven groups of 5 each, and were treated with piperazine citrate, per os, at rates of 110 mg/kg (PC), 110 mg/kg (PC in AMS), 82.5 mg/kg (PC), 82.5 mg/kg (PC in AMS), 55 mg/kg (PC) and 55 mg/kg (PC in AMS) respectively. The seventh group served as untreated control. Mean Eggs Per Gramm of faeces (EPG) were 375 ± 32.27, 175 ± 14.43, 830 ± 1.04, 70 ± 12.25, 850 ± 293.06, 370 ± 58.54 and 2,200 ± 2.55 respectively. This showed EPG reduction rates of 83%, 92%, 62%, 97%, 61% and 83% among the respective treated groups.展开更多
The recent events and constant global changes show the importance of rethinking city planning.In this context,the 15-Minute City concept got important as it brings people closer to activities and services,through shor...The recent events and constant global changes show the importance of rethinking city planning.In this context,the 15-Minute City concept got important as it brings people closer to activities and services,through short trips by active modes,being the key to a sustainable city.Based on this concept,this paper analysed the spatial accessibility of residents of Belo Horizonte(Brazil)to two establishments essential to the quality of life:bakeries and supermarkets.The analyses were made through the influence areas,spatial clusters,and the Local Indicators of Spatial Association.The results showed that bakeries are more accessible than supermarkets,which are not accessible to the entire population,especially in low-density and low-income regions.In addition,areas with potential for new projects were identified by the relationship between existing facilities(supermarkets or bakeries)and population density/income.Finally,the results highlight the challenges for developing sustainable cities considering the 15-Minute City concept throughout the territory of Belo Horizonte.展开更多
为检测烘焙类食品中的叶黄素酯以及筛选无乙醚的萃取溶剂,本文对烘焙产品中的叶黄素酯皂化时间、KOH浓度以及不同萃取溶剂的萃取效果进行研究。结果表明检测烘焙食品中叶黄素酯的皂化最优条件为:2 g样品(面糊/面团),0.2 g BHT,10 mL无...为检测烘焙类食品中的叶黄素酯以及筛选无乙醚的萃取溶剂,本文对烘焙产品中的叶黄素酯皂化时间、KOH浓度以及不同萃取溶剂的萃取效果进行研究。结果表明检测烘焙食品中叶黄素酯的皂化最优条件为:2 g样品(面糊/面团),0.2 g BHT,10 mL无水乙醇,10 mL 60 g/100 mL KOH水溶液,室温振荡3 h。萃取溶剂环己烷:正己烷:乙酸乙酯=1:2:2为最佳萃取剂,回收率为94.31%~103.83%,精密度实验相对标准偏差均小于5%。表明该方法适合于烘焙类食品中叶黄素酯的提取及检测。展开更多
文摘Objective:To assess the ovicidal and larvicidal activities of aqueous and ethanolic extracts of pawpaw seeds Carica papaya（Caricaceae） on the eggs and first stage larvae（L<sub>1</sub>） of Heligmosomoides bakeri.Methods:Eggs of this parasite were obtained from experimentally infested mice（Mus musculus） and larvae were from eggs after incubation at 25℃for about 72 hours.The eggs and larvae were exposed to ten different concentrations（0.125,0.25,0.375,0.5, 0.75,1.0,1.25,1.75,2.25 and 2.75 mg/mL） of both aqueous and ethanolic extracts respectively for 72 hours.Distilled water and 0.05%ethanol used as placebo and negative control,respectively. Results:Placebo and negative control group all showed average 92%embryonnation,98%egg hatching and 2%larval mortality,and did not affect development and larval survival.The extracts inhibited embryonic development,egg hatching and larval survival.In general,the ovicidal and larvicidal activities increased with increasing concentration of different extracts.The aqueous extract was found to be more potent on eggs than on larvae.At 2.75 mg/mL,only 8%of eggs embryonnated and 50%hatched to L<sub>1</sub> vs 57%embryonic development and 79%hatching occurred in the ethanolic extract.However,this later extract was more efficient in preventing larval development producing 96%mortality as against 68%with the aqueous extract.Conclusions: These results shows the ovicidal and larvicidal properties of aqueous and ethanolic pawpaw seeds extracts.
基金Supported by the University of Dschang through the Laboratory of Applied Biology and Ecology(LABEA)with Grant No.462/550035/2012
文摘Objective:To evaluate the ovicidal and larvicidal activities of aqueous and ethanolic extracts of leaves of Dichrocephala integrifolia(D.integrifolia)against the eggs(fresh and embryonnated),the first and second larval stages of Heligmosomoides bakeri.In order to verify if this medicinal plant possesses active compounds capable of inhibiting the embryonation and hatching of eggs or to induce the mortality of larvae(L1 and L2).Methods:Dried extracts were diluted in distilled water to obtain five different concentrations:625,1 250,2500,3750 and 5000μg/mL.Fresh eggs obtained from artificially infected mice feces were exposed to these different concentrations for 48 h.Time of contact for embryonated eggs was 6 h while L1 and L2 larvae were exposed for 24 h.Distilled water(placebo)and 1.5%DMSO were used as negative controls.Results:Distilled water,and1.5%DMSO had no effect on embryonation,hatching and larval survival.Aqueous extracts of D.integrifolia showed a weak activity against all stages of the parasite at all concentrations tested.On the contrary,the ethanolic extract of D.integrifolia inhibited the embryonation of 87.5%of fresh eggs,the hatching of 81.1%of embryonated eggs and induced the mortality of 98.1%and 98%of L1 and L2 larvae respectively at 5000μg/mL.Conclusions:The results of the present study indicate that the ethanolic extracts of D.integrifolia contained compounds with ovicidal and larvicidal properties.In spite of these results,in vivo tests,studies on toxicity and mechanism of action of active compounds are also needed to validate the utilisation of this medicinal plant by population of Dschang-Cameroon to treat gastro-intestinal parasites.
文摘To test effect of a synthetic Aluminium-Magnesium Silicate (AMS) on anthelmintic efficacy of piperazine citrate (PC), 35 mice were infected by dosing each, 0.15 ml Helignosomoides bakeri sample which contained 200 infective larvae, per os. Following comfirmation of establishment of infection by faecal floatation, they were assigned into seven groups of 5 each, and were treated with piperazine citrate, per os, at rates of 110 mg/kg (PC), 110 mg/kg (PC in AMS), 82.5 mg/kg (PC), 82.5 mg/kg (PC in AMS), 55 mg/kg (PC) and 55 mg/kg (PC in AMS) respectively. The seventh group served as untreated control. Mean Eggs Per Gramm of faeces (EPG) were 375 ± 32.27, 175 ± 14.43, 830 ± 1.04, 70 ± 12.25, 850 ± 293.06, 370 ± 58.54 and 2,200 ± 2.55 respectively. This showed EPG reduction rates of 83%, 92%, 62%, 97%, 61% and 83% among the respective treated groups.
文摘The recent events and constant global changes show the importance of rethinking city planning.In this context,the 15-Minute City concept got important as it brings people closer to activities and services,through short trips by active modes,being the key to a sustainable city.Based on this concept,this paper analysed the spatial accessibility of residents of Belo Horizonte(Brazil)to two establishments essential to the quality of life:bakeries and supermarkets.The analyses were made through the influence areas,spatial clusters,and the Local Indicators of Spatial Association.The results showed that bakeries are more accessible than supermarkets,which are not accessible to the entire population,especially in low-density and low-income regions.In addition,areas with potential for new projects were identified by the relationship between existing facilities(supermarkets or bakeries)and population density/income.Finally,the results highlight the challenges for developing sustainable cities considering the 15-Minute City concept throughout the territory of Belo Horizonte.
文摘为检测烘焙类食品中的叶黄素酯以及筛选无乙醚的萃取溶剂,本文对烘焙产品中的叶黄素酯皂化时间、KOH浓度以及不同萃取溶剂的萃取效果进行研究。结果表明检测烘焙食品中叶黄素酯的皂化最优条件为:2 g样品(面糊/面团),0.2 g BHT,10 mL无水乙醇,10 mL 60 g/100 mL KOH水溶液,室温振荡3 h。萃取溶剂环己烷:正己烷:乙酸乙酯=1:2:2为最佳萃取剂,回收率为94.31%~103.83%,精密度实验相对标准偏差均小于5%。表明该方法适合于烘焙类食品中叶黄素酯的提取及检测。
